The immune reaction and degradation fate of scaffold in cartilage/bone tissue engineering

Tissue engineering with scaffolds provides novel prospects for bone/cartilage damage healing. Previous studies mainly focus on the development of physical/chemical property of scaffold and their efficiency on tissue regeneration. The biocompatibility and biodegradation of scaffold have been questioned with their rapidly increased application, since the ultimate clinical application requires biological safety and efficiency of biomaterials. After scaffolds are implanted in living organisms, excessive inflammatory response and foreign body reaction may compromise tissue healing outcomes, or eventually lead to the failure of regeneration. Further, scaffolds degradation and degraded derivatives may elicit immunogenic reaction, cause environmental change, influence encapsulated drug/growth factor release and cellular activity. Hence, the understanding of the degradation characteristics of various biomaterials is required as well. Non-invasive monitoring the fate of scaffolds inside the body needs to be explored for temporally and longitudinally optical observation. The review mainly aims to provide a retrospective summary and discussion of the biocompatibility, immune response and fate of scaffold in cartilage/bone tissue engineering. The continuing development of sophisticated biocompatible and biomimetic scaffolds will eventually lead to clinical application which can improve the quality of patients' care and life.